The total mass of Earth's atmosphere is about $5.1480 \times 10^{18}$ kg. The carbon dioxide portion of that is about 0.058% by mass. Of that, about 40% is "excess" carbon dioxide, above the pre-industrial average. So that all comes to be about 1.2 trillion metric tons ($1.2 \times 10^{15}$ kg), which getting that to Mars would represent a significant challenge in and of itself.
The atmosphere of Mars is about 25 trillion metric tons ($2.5 \times 10^{16}$ kg), so in fact that would increase the atmospheric pressure of Mars by about 5%, which isn't that signficant. I'm not an expert in the math, but I believe that would be not be enough to trigger a "Runaway greenhouse effect" that would melt a large part of the Martian polar ice caps, which would in turn cause more running away of the temperatures.
Note there are much cheaper ways both to get rid of carbon dioxide on Earth and to bring greenhouse gases to Mars. See this article, which proposes manufacturing greenhouse gasses on Mars which are much more potent than Carbon Dioxide.